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  <title>Looks up a current parameter setting of the server</title>
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  <div id="layout-content"><div id="function.pg-parameter-status" class="refentry">
 <div class="refnamediv">
  <h1 class="refname">pg_parameter_status</h1>
  <p class="verinfo">(PHP 5, PHP 7)</p><p class="refpurpose"><span class="refname">pg_parameter_status</span> &mdash; <span class="dc-title">Looks up a current parameter setting of the server</span></p>

 </div>

 <div class="refsect1 description" id="refsect1-function.pg-parameter-status-description">
  <h3 class="title">说明</h3>
  <div class="methodsynopsis dc-description">
   <span class="methodname"><strong>pg_parameter_status</strong></span>
    ([ <span class="methodparam"><span class="type">resource</span> <code class="parameter">$connection</code></span>
   ], <span class="methodparam"><span class="type">string</span> <code class="parameter">$param_name</code></span>
   ) : <span class="type">string</span></div>

  <p class="para rdfs-comment">
    Looks up a current parameter setting of the server.
  </p>
  <p class="para">
    Certain parameter values are reported by the server automatically at 
    connection startup or whenever their values change. <span class="function"><strong>pg_parameter_status()</strong></span> can be 
    used to interrogate these settings. It returns the current value of a 
    parameter if known, or <strong><code>FALSE</code></strong> if the parameter is not known.
  </p>
  <p class="para">
    Parameters reported as of PostgreSQL 8.0 include <em>server_version</em>, 
    <em>server_encoding</em>, <em>client_encoding</em>, 
    <em>is_superuser</em>, <em>session_authorization</em>, 
    <em>DateStyle</em>, <em>TimeZone</em>, and <em>integer_datetimes</em>.
    (<em>server_encoding</em>, <em>TimeZone</em>, and 
    <em>integer_datetimes</em> were not reported by releases before 8.0.) Note that 
    <em>server_version</em>, <em>server_encoding</em> and <em>integer_datetimes</em> 
    cannot change after PostgreSQL startup.
  </p>
  <p class="para">
    PostgreSQL 7.3 or lower servers do not report parameter settings,
    <span class="function"><strong>pg_parameter_status()</strong></span>
    includes logic to obtain values for <em>server_version</em> and 
    <em>client_encoding</em>
    anyway. Applications are encouraged to use <span class="function"><strong>pg_parameter_status()</strong></span> rather than ad 
    hoc code to determine these values.
  </p>
  <div class="caution"><strong class="caution">Caution</strong>
    <p class="para">
      On a pre-7.4
      PostgreSQL server, changing <em>client_encoding</em> via <em>SET</em> after connection startup will 
      not be reflected by <span class="function"><strong>pg_parameter_status()</strong></span>.
     </p>
  </div>
 </div>


 <div class="refsect1 parameters" id="refsect1-function.pg-parameter-status-parameters">
  <h3 class="title">参数</h3>
  <p class="para">
   <dl>

    
     <dt>
<code class="parameter">connection</code></dt>

     <dd>

      <p class="para">
       PostgreSQL database connection resource.  When 
       <code class="parameter">connection</code> is not present, the default connection 
       is used. The default connection is the last connection made by 
       <span class="function"><a href="pg_connect.html" class="function">pg_connect()</a></span> or <span class="function"><a href="pg_pconnect.html" class="function">pg_pconnect()</a></span>.
      </p>
     </dd>

    
    
     <dt>
<code class="parameter">param_name</code></dt>

     <dd>

        <p class="para">
         Possible <code class="parameter">param_name</code> values include <em>server_version</em>, 
        <em>server_encoding</em>, <em>client_encoding</em>, 
        <em>is_superuser</em>, <em>session_authorization</em>, 
        <em>DateStyle</em>, <em>TimeZone</em>, and 
        <em>integer_datetimes</em>.
        </p>
     </dd>

    
   </dl>

  </p>
 </div>


 <div class="refsect1 returnvalues" id="refsect1-function.pg-parameter-status-returnvalues">
  <h3 class="title">返回值</h3>
  <p class="para">A <span class="type"><a href="language.types.string.html" class="type string">string</a></span> containing the value of the parameter, <strong><code>FALSE</code></strong> on failure or invalid
  <code class="parameter">param_name</code>.</p>
 </div>


 <div class="refsect1 examples" id="refsect1-function.pg-parameter-status-examples">
  <h3 class="title">范例</h3>
  <p class="para">
   <div class="example" id="example-2507">
    <p><strong>Example #1 <span class="function"><strong>pg_parameter_status()</strong></span> example</strong></p>
    <div class="example-contents">
<div class="phpcode"><pre><span style="color: #000000">
<span style="color: #0000BB">&lt;?php<br />&nbsp;&nbsp;$dbconn&nbsp;</span><span style="color: #007700">=&nbsp;</span><span style="color: #0000BB">pg_connect</span><span style="color: #007700">(</span><span style="color: #DD0000">"dbname=publisher"</span><span style="color: #007700">)&nbsp;or&nbsp;die(</span><span style="color: #DD0000">"Could&nbsp;not&nbsp;connect"</span><span style="color: #007700">);<br /><br />&nbsp;&nbsp;echo&nbsp;</span><span style="color: #DD0000">"Server&nbsp;encoding:&nbsp;"</span><span style="color: #007700">,&nbsp;</span><span style="color: #0000BB">pg_parameter_status</span><span style="color: #007700">(</span><span style="color: #0000BB">$dbconn</span><span style="color: #007700">,&nbsp;</span><span style="color: #DD0000">"server_encoding"</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?&gt;</span>
</span>
</pre></div>
    </div>

    <div class="example-contents"><p>以上例程会输出：</p></div>
    <div class="example-contents screen">
<div class="cdata"><pre>
Server encoding: SQL_ASCII
</pre></div>
    </div>
   </div>
  </p>
 </div>

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